.container_{
  width: $max-width;
}
.video_box{
  height:$video-box-height;
}
.material_box{
  width: $material-box-width;
}
.board{
  width: $board-width;
  height: $board-height;
}
.video{
  .v_box{
    width: $student-teacher-video-width;
    height: $student-teacher-video-height;
  }
}
.ppt_set{
  height: $setting-height;
  width: $board-width;
}
.video_set{
  height: $setting-height;
  width: $student-teacher-video-width;
}
.chat{
  width: $chat-width;
  height: $chat-height;
}
.bottom-panel{
  height: $bottom-panel-height;
}

@media screen  and (max-width: 1366px)  {
  .container_{width:1152px}
  .video_box{height:404px}
  .material_box{width:812px}
  .board{width:540px;height:405px}
  .video .v_box{width:272px;height:202px}
  .ppt_set{height:56px;width:540px}
  .video_set{height:56px;width:272px}
  .chat{width:340px;height:628px}
  .bottom-panel{height:168px}
  //-----------
  .sendMsg .sendBtn{
    margin-top: 1px !important;
  }
}
@media screen and (min-width: 1366px) and (max-width: 1600px)  {
  .container_{width:1276px}
  .video_box{height:468px}
  .material_box{width:936px}
  .board{width:624px;height:468px}
  .video .v_box{width:312px;height:234px}
  .ppt_set{height:56px;width:624px}
  .video_set{height:56px;width:312px}
  .chat{width:340px;height:724px}
}
@media screen and (min-width: 1600px) and (max-width: 1990px)  {
  .container_{width:1360px}
  .video_box{height:510px}
  .material_box{width:1020px}
  .board{width:680px;height:510px}
  .video .v_box{width:340px;height:255px}
  .ppt_set{height:56px;width:680px}
  .video_set{height:56px;width:340px}
  .chat{width:340px;height:766px}
  .bottom-panel{height:200px}
}